I don´t understand that. In the WoD ending cinematic, Archimonde is saying to Gul´Dan: "We have a Pact.". And why Sargeras has a pact now? And with who? With Archimonde or Gul´Dan? I think that this turnes out to be that Archimonde and Sargeras had a Pact to summon the Burning Legion to Draenor with the goal to stop Grommash, Yrel, Khadgar and us and that Gul´Dan is responsible for this mission. The second possiblity is that Sargeras is coming to Azeroth after Archimonde failed (again), but this is not fitting in an expansion with Azshara at all.

Originally Posted by WildberryFan

Day 21
Jailor awakens.

A Jailor is a keeper of something. Maybe it is referring to Tyr who is keeping that what is under Tirisfal and who is now awakening.

Originally Posted by WildberryFan

Day 22
You defeated Gul'dan. Do you want to continue?

I think that this is referring to "the next step" with the Burning Legion. Is the Legion finally coming to Azeroth? Maybe.

It can wear mail
It can use ranged weapons
It fits WoW's armor/weapon system
It can use shadow and tech abilities
It can be tied to a Sylvanas/Vol'jin/Azshara expansion
It looks edgy and dark
Its the polar opposite of the previous class; Monks